The present invention relates to stick lever units for radio-controlled devices, which remotely maneuver controllable bodies, such as model airplanes, model helicopters, and cars, or boats, by controlling a stick lever. More particularly, the present invention relates to radio-controlled devices, having the stick lever unit.
A stick lever unit for radio control (hereinafter, referred to as a stick lever unit) is equipped on radio-controlled devices (radio-control devices for models), each of which remotely controls manipulated bodies, such as model airplanes, model helicopters, model cars, and model boats (refer to Japanese Utility Model Publication No. 62-87697).
The stick lever unit is shown in FIG. 9. In the conventional radio control unit 1, two sets of right and left stick lever units 2 are respectively equipped horizontally on the upper portion of the front surface thereof. The stick lever of each stick lever unit 2 is operated vertically and horizontally. The stick lever unit 2 is manipulated to control proportional control signals carried with radio waves transmitted to a controllable body from the radio-controlled device. Thus, the stick lever unit 2 controls operational movements of various servomechanisms mounted on the controllable body to remotely control the controllable body.
Such stick lever units include a stick lever returning mechanism that automatically returns the stick lever to a predetermined neutral position when the operator takes off the stick lever in an operation state of the stick lever in a certain operation direction or a stick lever holding mechanism that maintains the stick lever at its position even when the operator takes off his fingers in the stick lever operational state. For example, the stick lever return mechanism is equipped in the operational direction of the stick lever, which controls the aileron, rudder and the elevator, which control the flight direction of an airplane. Moreover, instead of installation of the return mechanism, the stick lever holding mechanism that maintains the control volume, even when an operator takes off his fingers from the stick lever, to maintain the number of revolutions of the engine in a constant value during flight, for example, is equipped in the operation direction of the stick lever, which controls the output of the model engine of the model airplane.
The stick lever unit including the stick lever return mechanism and the stick lever holding mechanism will be described specifically here by referring to the drawings. FIGS. 10 and 11 illustrate a conventional stick lever unit. FIG. 10 is a plan view illustrating the conventional stick lever unit. FIG. 11 is the rear view illustrating the conventional stick lever unit. First, the basic configuration of the stick lever unit will be explained below.
The stick lever unit 2 includes a fixing frame 21 acting as a fixing member, a rotational frame 22 and a rotational control element 23, acting as rotational members, and a stick lever 24 mounted on the rotational control element 23. A substantially rectangular window 21a penetrates in the center of the fixing frame 21. The rotational frame 22, being a semi-cylindrical member, is journaled rotatably on the rotational shaft 25a (acting as one rotational shaft) of the variable resistor 25 attached to the fixing frame 21 and the rotational shaft 22a (acting as the other rotational shaft) thereof attached to the rotational frame 22.
A small rectangular window 22b is formed in the center of the rotational frame 22. The rotational control element 23 attached to the stick frame 24 is rotatably fit loosely within the small window 22b. The rotational shaft of the rotational control element 23 is made of the rotational shaft 26a of the variable resistor 26 fixed to the rotational frame 22. One end of the rotational shaft 26a is journaled in the rotational frame 22. In this configuration, when an operator manipulates the stick lever 24 vertically, horizontally, and slantingly, the rotational frame 22 and the rotational control element 23 rotate and the variable resistors 25 and 26 rotate, so that the output signals to the manipulated object are controlled.
Next, the configurations of the return mechanism and the holding mechanism of the stick lever 24 in the stick lever unit 2 will be described blow.
As shown in drawings, in the return mechanism of the stick lever 24, two contact pins 27 and 27 are disposed to the rotational control element 23. An arm 28 and a spring 29 are disposed to the rotational frame 22. The arm 28 has one end 28a rotationally attached to the rotational frame 22 and the other end 28b attached to the spring 29. Thus, the arm 28 acts to always depress against the contact pins 27, 27. Accordingly, when the stick lever 24 rotates the rotational control element 23, one of the contact pins 27 is pressed to the arm 28. When the stick lever 24 is released, the rotational control element 23 automatically returns to the predetermined original position.
In addition, in the configuration of the holding mechanism of the stick lever 24, an arc-shaped groove 22c is formed in the rotational frame 22. The groove 22 is in a fan-shaped form with respect to the rotational shaft 22a acting as the center and has an outer circumference with gear-shaped groove therein. A resilient plate 30 acting as a pressure member is attached to the fixing frame 21. When the resilient plate 30 presses the arc-shaped groove 22c, a resistance force occurs against the rotational operation of the rotational frame 22. As a result, the stick lever 24 is held at the position where it has been rotated.
In the stick lever holding mechanism, because the one end of the resilient plate 30 is fastened on the fixing frame 21 with a screw, the spaced distance between the resilient plate 30 and the fixing frame 22 can be adjusted. By turning the adjustment screw, that configuration allows the pressure force of the pressure member working on the arc-shaped groove 22c as a stick lever holding mechanism to be freely adjusted. (Refer to Japanese Utility Model Publication No. 62-87697)
In such a stick lever unit, a different type of resilient plate (pressure member) configuring a stick lever holding mechanism is used according to the object manipulated by a radio-controlled device. For example, in the stick lever unit for manipulating a model airplane, a ratchet-type resilient plate having a protrusion in the resilient slate which is engaged with the arc-shaped groove to hold stepwise operation positions of the stick lever may be used. In model helicopters, a brake-type resilient plate having a flat resilient plate without protrusion, which can steplessly hold the operation positions of the stick lever by engaging the resilient plate to the arc-shaped groove may be used.
Conventionally, the manufacturer specified the resilient plate for radio-controlled devices attached to the stick lever unit and mounted the stick lever unit to the radio-controlled device for shipping as a complete device. For that reason, when a user wants to change the resilient plate after purchase of the product, the installed resilient plate is removed after opening the housing of the radio-controlled device body to replace it for other type of resilient plate. This work has been troublesome.
Further, when a resilient plate to be replaced is not at hand or the user himself cannot replace the resilient plate, the product has to be sent to the manufacturer to ask for the replacement of the resilient plate. This is troublesome and takes much time which is very inconvenient.